\section{Conclusion}
\label{section:conclusion}

In this report, we measured four key aspects of how a file system works internally, namely the ideal buffer size for random access, the file system prefetch size for sequential access, the file cache size, and at which point does file system add additional layers of indirection. Our measurements on the non-virtualized system confirmed our hypothesis, and give us some accurate estimations of these file system internals. However, the same experiments conducted in a virtualized system is complicated by the virtualization techniques and the guest/host interaction. Thus the behavior of a virtualized system is much less creditable than a non-virtualized system, and we need new techniques to measure and understand how a virtualized system works.
